Decline in wheat yields likely due to changing climate

"These model predictions will be used along with economic models to study and understand world food security and adaptation capacity in both developing and developed countries

Global wheat production can be expected to fall by 6% for each degree centigrade of temperature increase together with increased variability of yield across regions and seasons; that is the main finding of an international consortium of researchers including the James Hutton Institute, who have used a systematic multi-model test to make use of data from field and artificial heating experiments to focus on the responses of wheat to high temperatures.

The researchers tested thirty different wheat crop models within the Agricultural Model Inter-comparison and Improvement Project (AgMIP) against field experiments in which growing season mean temperatures ranged from 15 °C to 32 °C, including experiments with artificial heating.

Results indicate that warming is already slowing yield gains at a majority of wheat-growing locations, and that each °C of further temperature increase means a projected fall of 6% in global wheat production, becoming more variable over space and time.

Dr Davide Cammarano, researcher at the Information and Computational Sciences Group at the James Hutton Institute and contributor to the study, said: “Comparison and improvement of crop models is important in order to have more reliable predictions in the face of climate change. Within AgMIP these model predictions will be used along with economic models to study and understand world food security and adaptation capacity in both developing and developed countries.

“Improved crop models can be also applied to Scotland because the inputs needed by the models, such as soil, weather and crop management, are location-specific. Therefore, by changing these inputs the model will be able to predict and understand the patterns of crop production and food security for Scotland, or any part of the world.

“This is truly an international research effort, as many crop modellers, experimentalists, crop physiologists, and breeders, from across the world have joined forces to make this happen.”

Dr Robin Matthews, research leader at the Institute, commented: “The challenge of delivering food security is immense, as it is essential that it should not be addressed in isolation from the other challenges facing mankind such as climate change, population increase and declining non-renewable resources.”

Notes to editors:

The paper 'Rising temperatures reduce global wheat production', by S. Asseng et al, is available from Nature Climate Change, and more information about AgMIP can be found on the project website.